The effect of a hemofilter during extracorporeal circulation on hemodynamics in patients with SIRS

Objective: To evaluate the hypothesis that extracorporeal hemopurification with a hemofilter contributes to the stabilization of hemodynamics in patients with systemic inflammatory response syndrome (SIRS) due to a mechanism other than the removal of cytokines. Design: Prospective study. Setting: Intensive care unit (ICU) in a university hospital. Patients: Seven critically ill patients who met criteria for SIRS with unstable hemodynamics requiring vasopressors after emergency surgery. Interventions: Before initiation of continuous hemofiltration (CHF) extracorporeal circulation through the hemofilter (ECC) with a hollow-fiber polyacrylonitrile hemofilter was performed for 6 h. Measurements and results: Vital signs were monitored continuously and hemodynamics were evaluated intermittently. The blood level of endotoxin and the plasma levels of cytokines were measured at 0 and 6 h. Changes in plasma levels of cytokines passing through the hemofilter were evaluated at 3 h. A significant decrease of body temperature (P < 0.05 at 3 and 6 h vs 0 h), a significant elevation of mean arterial pressure (P < 0.05 at 0.5 h, P < 0.01 at 3 and 6 h vs Oh), and a significant increase of urinary flow rate (P < 0.05 at 0 to 3 h vs -3 to 0 h) were observed with ECC. Neither the blood level of endotoxin nor the plasma levels of cytokines decreased. A significant increase of plasma IL-6 as it passed through the hemofilter was noted. Conclusions: The beneficial effects of hemopurification with a hemofilter on SIPS patients are possibly due to mechanisms other than the elimination of cytokines with ultrafiltration, diffusion, or adsorption.